1. You must adjust the Makefile depending on the exact version of XULRunner which is installed when you run the Makefile. The line to check/adjust is the fourth one which begins with "PLUGIN_INCLUDE" - look for the name of the directory "xulrunner-1.9xxx" within the directory "/usr/include".
2. The Makefile above works fine on openSUSE 11.0 64-bit running the 64-bit version of Firefox. If you use the 32-bit version of openSUSE, or the 32-bit version of Firefox on the 64-bit version of openSUSE, then it should work if you replace all occurrences of "lib64" with "lib".

4. Installation Instructions

Extract all of the files in the "tar.gz" archive.

Change the "Makefile" to the version shown above.

Open a command prompt and navigate to the directory where the unpacked set of files exists.

Type in "Make clean" and press enter.

Type in "Make" and press enter.You will probably receive two warnings which can be ignored.

Type in "Make plugin" and press enter.

Type in "su -c checkinstall", and enter the password for "root".
(This creates an RPM package so that the software shows up in YAST.)

Make sure that the directory written to by step 7 is defined as a "Software Repository". On a 64-bit system this should be "/usr/src/packages/RPMS/x86_64/".

Install the package using YaST. Set the "Filter" to "Repositories" and choose the repository set up in step 8.